System, apparatus, and method for resin level maintenance in a stereo-lithography device

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. Provisional Patent Application No. 61/232,449, filed Aug. 9, 2009, and is incorporated herein by reference.

BACKGROUND

Stereo-lithography devices utilize a viscous fluid that is responsive to light to form a solid material. The viscous fluid is typically a resin, and may be a filled resin, that can cause significant wear on a pump. During manufacturing operations, it is desirable that a resin fluid level is properly maintained so that precision parts can be properly prepared from the stereo-lithography operations. Therefore, further technological developments are desirable in this area.

SUMMARY

One embodiment is a unique method for maintaining a resin level in a manufacturing process. Further embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

<figref idrefs="DRAWINGS">FIG. 1</figref> is a schematic illustration of a system for leveling a fluid reservoir in a stereo-lithography device.

<figref idrefs="DRAWINGS">FIG. 2</figref> is a schematic illustration of another system for leveling a fluid reservoir in a stereo-lithography device.

<figref idrefs="DRAWINGS">FIG. 3</figref> is a schematic illustration of yet another system for leveling a fluid reservoir in a stereo-lithography device.

DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, any alterations and further modifications in the illustrated embodiments, and any further applications of the principles of the invention as illustrated therein as would normally occur to one skilled in the art to which the invention relates are contemplated herein.

<figref idrefs="DRAWINGS">FIG. 1</figref> is a schematic diagram of a system <b>100</b>, including a stereo-lithography device <b>102</b> having a primary fluid vessel <b>104</b> having an amount of a photo-curable fluid <b>105</b> therein. The stereo-lithography device <b>102</b> may be any type of device understood in the art, and may include a manufacturing controller <b>130</b> that reads an electronic instruction file, an optical device <b>128</b> (e.g. a laser, projector, lens, prism, and/or mirror), and a support <b>107</b> for a manufactured component <b>132</b>. The support <b>107</b> may be configured to hold the manufactured component <b>132</b> stationary, or may be configured to move the manufactured component <b>132</b> during manufacturing operations. For example, the support <b>107</b> may lower the manufactured component <b>132</b> as subsequent layers of the component <b>132</b> are added.

The photo-curable fluid <b>105</b> has a surface <b>106</b> where the optical device <b>128</b> projects light, curing the fluid and forming the component <b>132</b> at the position where the light strikes the surface <b>106</b>. The surface <b>106</b> is specifically positioned relative to the optical device <b>128</b>, for example at the focal length of the optical device <b>128</b>, and the focal length of the optical device <b>128</b> may be configurable during a manufacturing operation. Additionally, the surface <b>106</b> may tend to vary during manufacturing operations, for example as the fluid <b>105</b> is consumed during the manufacturing process, or as the component <b>132</b> is raised from or lowered into the fluid <b>105</b> (e.g. between manufacturing subsequent layers of the component).

The system <b>100</b> further includes a leveling reservoir <b>112</b> fluidly coupled to the primary fluid vessel <b>104</b> (e.g. through a flexible fluid conduit <b>108</b>), where a fluid level of the fluid in the leveling reservoir <b>112</b> is vertically positionable. The schematic illustration of <figref idrefs="DRAWINGS">FIG. 1</figref> shows a vertical positioning device <b>114</b> coupled to an electronic motor <b>116</b> controllable by a controller <b>126</b>. The vertical positioning device <b>114</b> in <figref idrefs="DRAWINGS">FIG. 1</figref> controls the fluid level <b>106</b> in the leveling reservoir <b>112</b> by vertically moving the leveling reservoir <b>112</b>. When the leveling reservoir <b>112</b> is raised, fluid flows from the leveling reservoir <b>112</b> into the primary fluid vessel <b>104</b>, raising the fluid level <b>106</b> slightly in both vessels <b>104</b>, <b>112</b>. When the leveling reservoir <b>112</b> is lowered, fluid flows from the primary fluid vessel <b>104</b> into the leveling reservoir <b>112</b>, lowering the fluid level <b>106</b> slightly in both vessels. Thereby, the controller <b>126</b> can re-establish the fluid level <b>106</b> at the pre-determined level, during manufacturing operations and/or between manufacturing stages while manufacturing the component <b>132</b>.

The controller <b>126</b> is structured to perform certain operations to maintain the fluid level <b>106</b>. In certain embodiments, the controller <b>126</b> forms a portion of a processing subsystem including one or more computing devices having memory, processing, and communication hardware. The controller <b>126</b> may be a single device or a distributed device, and the functions of the controller may be performed by hardware or software. In certain embodiments, at least some operations of the controller <b>126</b> may be performed manually by an operator (not shown).

The exemplary device illustrates the logical connections, but any type of device providing a controller <b>126</b> (including a manual operator) that has an actuator <b>116</b> to control a vertical position of the leveling reservoir <b>112</b> is contemplated herein. One of skill in the art will recognize that a small leveling reservoir <b>112</b> surface area relative to the primary fluid vessel <b>104</b> surface area will allow more precise control of the primary fluid vessel <b>104</b> surface area (i.e. larger changes in the leveling reservoir <b>112</b> create smaller changes in the fluid level <b>106</b>) while a larger leveling reservoir <b>112</b> surface area relative to the primary fluid vessel <b>104</b> surface area allows the leveling reservoir <b>112</b> to replace a greater amount of fluid <b>105</b> during the leveling operations. The leveling reservoir <b>112</b> is illustrated with a constant cross-sectional area as a function of vertical position along the leveling reservoir <b>112</b>, but the cross-sectional area can vary.

One of skill in the art can determine the need for precision versus fluid volume, also accounting for the total available vertical movement of the leveling reservoir <b>112</b> due to any limitations such as the physical space available, the type and capability of the actuator <b>116</b> or vertical positioning device <b>114</b>, etc. The presented leveling reservoir <b>112</b> configuration with the primary fluid vessel <b>104</b> allows the system <b>100</b> to maintain the proper fluid level <b>106</b> during manufacturing operations without exposing any moving parts to the fluid <b>105</b>. In certain embodiments, the controller <b>126</b> maintains a pre-determined level of the photo-curable fluid <b>105</b> in the primary fluid vessel <b>104</b> by vertically moving the leveling reservoir <b>112</b>.

The system <b>100</b> further includes a replenishment reservoir <b>118</b> selectively fluidly coupled with the primary fluid vessel <b>104</b>, for example through a fluid conduit <b>110</b>. In certain embodiments, a valve (not shown) operable by the controller <b>126</b> is interposed between the replenishment reservoir <b>118</b> and the primary fluid vessel <b>104</b>, although in other embodiments, the replenishment reservoir <b>118</b> is fluidly coupled to the primary fluid vessel <b>104</b> at all times. The fluid coupling between the replenishment reservoir <b>118</b> and the primary fluid vessel <b>104</b> may also occur through the leveling reservoir <b>112</b>, or the leveling reservoir <b>112</b> may be fluidly coupled with the primary fluid vessel <b>104</b> through the replenishment reservoir <b>118</b>. One of skill in the art will recognize that, if the replacement reservoir <b>118</b> is fluidly coupled to the primary fluid vessel <b>104</b> during the leveling operations of the leveling reservoir <b>112</b>, the surface area of the replenishment reservoir <b>118</b> will affect the precision and volume capacity of the leveling reservoir <b>112</b>. The replenishment reservoir <b>118</b> may be fluidly coupled with the primary fluid vessel <b>104</b> during leveling operations or not. In certain embodiments, the replenishment reservoir <b>118</b> is fluidly coupled to the primary fluid vessel <b>104</b> before and after manufacturing operations of the stereo-lithography device <b>102</b>, and is de-coupled to the primary fluid vessel <b>104</b> during manufacturing operations of the stereo-lithography device <b>102</b>.

In certain embodiments, the pre-determined level of the photo-curable fluid <b>105</b> in the primary fluid vessel <b>104</b> corresponds to a focal plane of the optical device <b>128</b> of the stereo-lithography device <b>102</b>. The controller <b>126</b> may be further structured to transfer fluid between the replenishment reservoir <b>118</b> and primary fluid vessel <b>104</b> in response to the stereo-lithography device <b>102</b> completing a layer of a component <b>132</b> being manufactured by the device <b>102</b>, in response to the stereo-lithography device <b>102</b> completing a specified number of layers of the component <b>132</b>, and/or in response to the manufacturing process of the component consuming a specified amount of the photo-curable fluid <b>105</b>.

In an exemplary embodiment, the leveling reservoir <b>112</b> is moved to a default position prior to an operation of the stereo-lithography device <b>102</b> to manufacture a layer of a component <b>132</b>, and a fluid level of the replenishment fluid in the replenishment reservoir <b>118</b> is moved such that the level <b>106</b> of the photo-curable fluid <b>105</b> in the primary fluid vessel <b>104</b> is at the pre-determined level prior to the operation of the stereo-lithography device <b>102</b> to manufacture a layer of a component <b>132</b>. In the illustrated embodiment, the fluid level of the replenishment fluid in the replenishment reservoir <b>118</b> is controlled by moving the replenishment reservoir <b>118</b> vertically with a vertical positioning device <b>120</b> responding to an actuator <b>124</b> controlled by the controller <b>126</b>. In one example, the leveling reservoir <b>112</b> is positioned at a default position such as a position centered around the fluid level <b>106</b>, a position to allow maximum raising of the leveling reservoir <b>112</b> during manufacturing operations, or a position allowing maximum lowering of the leveling reservoir <b>112</b> during manufacturing operations. The pre-determined level may be changed in response to the stereo-lithography device <b>102</b> completing a layer of a component <b>132</b> being manufactured by the device <b>102</b>.

Referencing <figref idrefs="DRAWINGS">FIG. 2</figref>, an alternate embodiment of a system <b>200</b> for leveling a fluid reservoir in a stereo-lithography device is shown. The system <b>200</b> includes the actuator <b>116</b> that moves a plunger <b>204</b> to control the fluid level in the leveling reservoir <b>112</b>. Additionally or alternatively, the system <b>200</b> includes an actuator <b>124</b> that moves a plunger <b>202</b> to control the fluid level in the replenishment reservoir <b>118</b>.

Referencing <figref idrefs="DRAWINGS">FIG. 3</figref>, yet another embodiment of a system <b>300</b> for leveling a fluid reservoir in a stereo-lithography device is shown. The system <b>300</b> includes a pump <b>306</b> that controls an overpressure in the leveling reservoir <b>112</b>. The overpressure in the leveling reservoir <b>112</b>, for example an air pressure in the space above the fluid <b>105</b>, controls the level of the fluid in the leveling reservoir <b>112</b>. Any pressure-controlled fluid level control is contemplated herein. The specific illustration of <figref idrefs="DRAWINGS">FIG. 3</figref> shows a biasing force (e.g. a spring <b>302</b>) that tends to push the fluid level higher, with the overpressure opposing the spring <b>302</b> and controlling the fluid level. Similarly, a pump <b>308</b> provides an overpressure in the replenishment reservoir <b>118</b>, which may act against a spring <b>304</b>, to control the fluid level in the replenishment reservoir <b>118</b>.

An exemplary technique for leveling a resin fluid in a stereo-lithography device is described. The technique includes an operation to provide a stereo-lithography device having a primary fluid vessel having an amount of a photo-curable fluid therein, and an operation to provide a leveling reservoir fluidly coupled to the primary fluid vessel. A fluid level in the leveling reservoir is vertically positionable. The technique includes an operation to provide a replenishment reservoir fluidly coupled to the primary fluid vessel, where a fluid level in the replenishment reservoir is also vertically positionable. The technique includes an operation to position the replenishment fluid level in the replenishment reservoir such that a photo-curable fluid level in the primary fluid vessel is at a pre-determined level. The technique further includes an operation to manufacture a layer of a component in the primary fluid vessel and an operation to maintain the pre-determined level of the photo-curable fluid in the primary fluid vessel during the manufacturing by vertically positioning the fluid level in the leveling reservoir.

In certain embodiments, the technique further includes an operation to add a photo-curable fluid to the primary fluid vessel, and an operation to move the fluid level in the replenishment reservoir and/or the fluid level in the leveling reservoir to return a level of the photo-curable fluid level to the pre-determined level. An exemplary embodiment includes vertically positioning the fluid level in the leveling reservoir by vertically moving the leveling reservoir. Another exemplary embodiment includes vertically positioning the fluid level in the leveling reservoir by moving a piston that causes the fluid level in the leveling reservoir to move. Another exemplary embodiment includes vertically positioning the fluid level in the leveling reservoir by controlling an overpressure in the leveling reservoir, where the amount of the overpressure positions the fluid level in the leveling reservoir. Any operation described to vertically position the fluid level in the leveling reservoir may also be used to vertically position the fluid level in the replenishment reservoir.

An exemplary technique further includes an operation to vertically position the fluid level in the leveling reservoir by vertically moving the leveling reservoir, and further includes an operation to position the leveling reservoir at a default position before the operation to position the replenishment fluid level in the replenishment reservoir such that the photo-curable fluid level in the primary fluid vessel is at a pre-determined level. Thereby, the technique provides the leveling reservoir with a pre-determined amount of leveling fluid available in the leveling reservoir before the operation to manufacture the layer of the component. The exemplary technique further includes an operation to repeat the operation to position the leveling reservoir to the default position, and to repeat the operation to position the replenishment reservoir such that a photo-curable fluid level in the primary fluid vessel is at the pre-determined level in response to completing the manufacturing of the layer of the component in the primary fluid vessel. An exemplary technique further includes an operation to change the pre-determined level in response to completing the operation to manufacture the layer of a component in the primary fluid vessel. An exemplary pre-determined level is a focal plane of an optical device of the stereo-lithography device.

As is evident from the figures and text presented above, a variety of embodiments according to the present invention are contemplated.

One exemplary embodiment is a system, including a stereo-lithography device having a primary fluid vessel having an amount of a photo-curable fluid therein, a leveling reservoir fluidly coupled to the primary fluid vessel, a fluid level in the leveling reservoir being vertically positionable, and a controller structured to maintain a pre-determined level of the photo-curable fluid in the primary fluid vessel by vertically positioning the fluid level in the leveling reservoir. The system further includes a replenishment reservoir selectively fluidly coupled with the primary fluid vessel, wherein the controller is further structured to transfer fluid between the replenishment reservoir and the primary fluid vessel.

In certain embodiments, the pre-determined level of the photo-curable fluid in the primary fluid vessel corresponds to a focal plane of an optical device of the stereo-lithography device. The controller may be further structured to transfer fluid between the replenishment reservoir and primary fluid vessel in response to the stereo-lithography device completing a layer of a component being manufactured by the device. In an exemplary embodiment, the fluid level in the leveling reservoir is positioned by moving the leveling reservoir vertically, and the leveling reservoir is moved to a default position prior to an operation of the stereo-lithography device to manufacture a layer of a component. The fluid level in the replenishment reservoir is moved such that the level of the photo-curable fluid in the primary fluid vessel is at the pre-determined level prior to the operation of the stereo-lithography device to manufacture a layer of a component. The pre-determined level may be changed in response to the stereo-lithography device completing a layer of a component being manufactured by the device. The default position includes a position determined in response to the pre-determined level.

Another exemplary embodiment is a method including providing a stereo-lithography device having a primary fluid vessel having an amount of a photo-curable fluid therein, providing a leveling reservoir fluidly coupled to the primary fluid vessel, the leveling reservoir having a fluid level that is vertically positionable, and providing a replenishment reservoir fluidly coupled to the primary fluid vessel. The replenishment reservoir has a fluid level that is vertically positionable. In certain embodiments, the fluid level in the leveling reservoir is vertically positioned by the vertical movement of the leveling reservoir, and the method further includes positioning the leveling reservoir to a default position, and then positioning the fluid level in the replenishment reservoir such that a photo-curable fluid level in the primary fluid vessel is at a pre-determined level before manufacturing a layer of the component in the primary fluid vessel. In certain embodiments, the method includes repeating the positioning the leveling reservoir to a default position and positioning the replenishment reservoir such that a photo-curable fluid level in the primary fluid vessel is at a pre-determined level in response to completing the manufacturing a layer of a component in the primary fluid vessel.

The method further includes maintaining the pre-determined level of the photo-curable fluid in the primary fluid vessel during the manufacturing by moving the fluid level in the leveling reservoir. The method further includes adding a photo-curable fluid to the primary fluid vessel, and moving the fluid level in the replenishment reservoir and/or the fluid level in the leveling reservoir to return a level of the photo-curable fluid level to the pre-determined level. The exemplary method includes changing the pre-determined level in response to completing the manufacturing a layer of a component in the primary fluid vessel, where the pre-determined level includes a focal plane of an optical device of the stereo-lithography device.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only certain exemplary embodiments have been shown and described and that all changes and modifications that come within the spirit of the inventions are desired to be protected. It should be understood that while the use of words such as preferable, preferably, preferred or more preferred utilized in the description above indicate that the feature so described may be more desirable, it nonetheless may not be necessary and embodiments lacking the same may be contemplated as within the scope of the invention, the scope being defined by the claims that follow. In reading the claims, it is intended that when words such as “a,” “an,” “at least one,” or “at least one portion” are used there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. When the language “at least a portion” and/or “a portion” is used the item can include a portion and/or the entire item unless specifically stated to the contrary.